export default function toThousands(num) {
  num = (num || 0).toString()
  let result = ''
  while (num.length > 3) {
    result = ',' + num.slice(-3) + result
    num = num.slice(0, num.length - 3)
  }
  if (num) {
    result = num + result
  }

  // 获取result的小数点‘.’的索引
  const n = result.indexOf('.')
  const strIndex = result.indexOf('.')
  // 如果有'.'
  if (n !== -1) {
    //  把'.'两侧的字符串拼接在一期，去掉最后这个','
    const result1 = result.substring(0, strIndex - 1)
    const result2 = result.substring(strIndex, result.length)
    result = result1 + result2
  }
  return result
}
